SeparatedItemStringBuilder.java

/*
 * Copyright (C) 2007-2010 J��lio Vilmar Gesser.
 * Copyright (C) 2011, 2013-2023 The JavaParser Team.
 *
 * This file is part of JavaParser.
 *
 * JavaParser can be used either under the terms of
 * a) the GNU Lesser General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 * b) the terms of the Apache License
 *
 * You should have received a copy of both licenses in LICENCE.LGPL and
 * LICENCE.APACHE. Please refer to those files for details.
 *
 * JavaParser is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 */
package com.github.javaparser.utils;

/**
 * Builds a string containing a list of items with a prefix, a postfix, and a separator.
 * <br>Example: (1,2,3) which has prefix "(", separator ",", postfix ")" and the items 1 through 3.
 * <p>Java 8 offers the very nice Collectors.joining(String, String, String) which does the same thing.
 */
public class SeparatedItemStringBuilder {

    private final String separator;

    private final String postfix;

    private boolean hasItems = false;

    private StringBuilder builder;

    public SeparatedItemStringBuilder(String prefix, String separator, String postfix) {
        builder = new StringBuilder(prefix);
        this.separator = separator;
        this.postfix = postfix;
    }

    /**
     * Add one item. Either pass a string, or a format for String.format and corresponding arguments.
     */
    public SeparatedItemStringBuilder append(CharSequence format, Object... args) {
        if (hasItems) {
            builder.append(separator);
        }
        builder.append(String.format(format.toString(), args));
        hasItems = true;
        return this;
    }

    public boolean hasItems() {
        return hasItems;
    }

    /**
     * Convert the builder into its final string representation.
     */
    @Override
    public String toString() {
        // This order of toStringing avoids debuggers from making a mess.
        return builder.toString() + postfix;
    }
}